Metal cleaning composition



Patented Oct. 10, 1950 NT, orFICE METAL CLEANING QQMPQSITION Arthur 0. Pabst, Douglaston, Y., and meanti- S. Salmon, New York, N. Y., assignors to Socony-Vacuum Oil Company, Incorporated, a

corporation of New York No Drawing.-

and in severe cases may be plugged to a point of. complete stoppage of coolant circulation. The composition of the deposits may vary depending upon the construction materials of the coolant system. Such metals as solder, copper, zinc, lead and iron may be used in one form or another and, of these, iron in its various modifications is the chief component. Grease mayenter the'cooling system from grease packed water pumps and oil or oxidized hydrocarbons may enter from blowby from the combustion chamber or from other sources. Certainother foreign deposits may be introduced with the coolant especially when it is water. A common component of the fouling deposits is iron oxide cemented fast to the metal surface by adsorbed or oxidized oil. Such a scale especially when covered with a"'coating of grease or oil is very difficult to remove.

Similar conditions prevail and similar contaminants consisting of oxidized metal and oily substances are usually present on the surfaces of machine parts which are to be cleaned in shops. The cleaning operations usually comprise degreasing, pickling and de-rusting.

' Cleaning compositions used at present for automotive cooling systems may be generally classified under one of three types. One type consists of an aqueous solution of an alkaline salt such as washing soda, trisodium phosphate, etc. This type acts Very slowly on rust and scale so that only small amounts of the deposits are removed in the time normally given the radiator flushing. Moreover it removes very little of the oil or grease deposits. A second type of cleaner consistsof an alkaline emulsion of hydrocarbon and other organic solvents. This type will remove the oil and grease deposits fairly satisfactorily but will remove only very small amounts of rust and scale deposit; consequently, the system is not entirely cleaned. The third type ofcleaner ccnslsts oi fate.

Application September 14, 1945, Serial No. 616,478

3 Claims. (Cl. 252-143) aqueous solutions of'acids or acid salts, such as hydrochloric and oxalic acids and sodium bisul- This type is very effective in removing rust and scale but will remove very little grease or oil deposit. Moreover, the acid type cleaner is highly corrosive and requires a follow-up flush with an alkali to stop the action of the acid. This is not always satisfactory in entirely avoiding corsurfaces Without causing rapid after corrosion of the metal surface.

Another object is the provision of a rapid method for cleaning metal surfaces and cooling systems which will not cause considerable surface corrosion. These and other objects will become apparent from the more detailed description of the invention following hereinafter.

We have now discovered that certain oil-inacid solution type emulsions will rapidly remove rust and Scale from metal surfaces and at the same time dissolve and emulsify any oil and grease present. Tests also indicate that the product has remarkable properties in inhibiting corrosion so that it is unnecessary to follow up with an alkaline'wash. In other words, the product offers the main advantages of each of the types of common radiator flushes without their disadvantages and failings. v I

These emulsions consist of a dispersed phase of an emulsifiable organic water-insoluble material and a continuous phase of a strong aqueous solution of hydrochloric acid, said solution being of the order of 4 pH or lower, and a specific emulsifying agent capable of producing emulsions sufliciently stable both for long shelf storage prior to use and for subsequent dilution if desired at the time of use While still forming a stable emulsion. The. aqueous phase as pointed out above is a strong solution of hydrochloric acid, sufficiently strong in the base composition to permit considerable dilution and still give a composition of sufficient strength for the ultimate cleaning purpose, that is the solution of scale, rust, sludge,

giving either a completely stable emulsion or a readily redispersable product when the emulsion is store-d over long periodsof time, for example as shelf goods. One such emulsifier is polyethylene-glycol mono iso-octyl phenyl ether. Another such emulsifier is l-hydroxyethyl 2- heptadecenyl glyoxalidine. A preferred form of composition is one which contains both of these emulsifiers in admixture.

The following examples will illustrate the type of emulsions made and used according to this invention:

Emulsion No. I II III IV V Weight Weight Weight Weight Weight Constituents per per per per per cent cent cent cent cent Orthodichlorbenzene. 20. 20. 0 20. 0 39. 19. 5 Kerosene 20. 0 l9. 5 19. 5 l9. 0 ConcentratedHCl (38%). 58. 5 27.0 27.0 27.0 59. 0 l-hydroxyethyLZ-heptadccenyl glyoxalidine.-- 1. 5 l. 5 5. 0 l. 5 Polyethylene-glycol, mono iso-octyl, phenyl other. 1. 5 1 0 Water 32. 0 32. 0 28. 5

These emulsions are prepared by dissolving the emulsifier in one of the phases, generally the one in which the emulsifier is most soluble, and then adding the other liquid phase while stirring the liquid with a higher speed mixer. The hydrocarbon emulsion in aqueous acid thus formed may be further diluted with water, if desired. Either the cationic emulsifier l-hydroxyethyl 2-heptadecenyl glyoxalidine or the non-ionic emulsifier, polyethyleneglycol mono iso-octyl phenyl ether are soluble in the oil phase and may be dissolved therein and the acid then added. Moreover, the former emulsifier is also soluble in aqueous acid solution, so that it may first be dissolved therein and the oil phase added with mixing. The'desirable amount of emulsifier to be used may vary between 0.1% to 5.0% by weight of the emulsion. In use the prepared emulsion may be added to the cooling system or to a circulating bath in concentrations controlled to provide the desired cleaning rate. Thus, for example, such prepared emulsions as shown in the above table may be added to water in a cooling system in concentrations of 5% emulsion and upwards. In any event the pH value of the liquid circulated in the cleaning system should be below 4.0. It will be noted that in Emulsions II and III in the above table, the concentrations of the I-ICl in the continuous phase is 17.4 percent by weight while in Emulsion V the concentration of HCl in the continuous phase is 38 percent by weight.

After the emulsion is added to the cooling system or cleaning bath, it is heated either by a heater or by starting the. engine involved and the heated emulsion is circulated. After about '20 and flushed by filling with water and running the 4 engine until warm. The water is then drained and the system refilled with cooling water. After such a treatment, the metal surfaces of the cooling system are thoroughly clean of rust, scale, Water deposits and grease. When the cleaning solution is used for cleaning metal parts or tools, the parts or tools are placed in a bath of the emulsion for a set period, then removed and rinsed in clean water. No neutralizing chemicals need be added to the rinsing water to prevent corrosion of the metal cleaned.

In addition to the practical tests on automobile cooling systems, as described hereinabove, laboratory tests were also made to establish the relative cleaning efficiencies of these novel emulsions and of certain cleaning composition used commercially heretofore. Rusted steel plates were immersed in the boiling solutions in concentrations recommended by the respective manufacturers, and the time required for completio of cleaning was taken as a measure of efficiency. The after corrosion of the metal was particularly noted.

gg g ggj Time, in After- Cleaning Compound tivc Acid or t cqrmslon Saltin Gleam o comp c c in four mg Bath cleaning days GmJliter Oxalic acid type 20 30 noticeable. Sodium bisulfate type 20 30 Do. Hydrochloric acid type... 23 7 strong. Emulsmn II (1 :9) 10 7 none.

It will be apparent from the above that the emulsions of this invention have substantially the same rust removing power as strong acid type commercial cleaning compositions while at the same time protecting the metal surface cleaned from after corrosion. Moreover, the emulsionshave a far greater grease and oil removing power than the acid or acid salt type cleaning compositions. The stable hydrocarbon-in-acidic-solution emulsion permits a uniformity of hydrocarbon distribution throughout the cleaning solution so that it may perform its function uniformly over the entire surface of the metal to be cleaned.

To further prove that the emulsion typ cleaning compositions of this invention are less corrosive on the metal surfaces or cooling systems being cleaned, even while being used, a number of uniform strips of the metals commonly encountered in cooling systems were immersed in several different cleaning liquids for a period of 24 hours and the corrosion loss was then measured.

It should be understood that the specific examples of the emulsion type cleaning composition and of their application as given hereinabove are intended merely as exemplary and are not to be construed as limiting the scope of this inven-' tion thereto. These compositions presenta very considerable and useful stability over related compositions known to the prior art as may be seen from the following data.

ACID EMULSION S Metal cleaning compositions 6 Normal HO] 59.0 59.0 59.0 59.0 59.0 59.0 59. Hydrocarbon solvents of kerosene boiling range 19.0 19.5 17. 19. 5 19. 5 19. 5 19. 5 Orthod1ch1orbenzene 19. 5 20.0 18. 5 20. 0 20. 0 20. O 20. 0 l-hydroxyethyl, 2-heptadecenyl, glyoxalidine. 1. 5 Polyethylene-glycol monoiso-octyl phenyl ether 1.0 Sodium Lauryl Sulnhate 1 5 5 0 Gum Tragacanth 1 l. 5 Polyethylene Glycol Monoleate 600 1. 5 Polyethylene Glycol Dioleate 600 1. 5 Polyethylene Glycol Oleate 400 L 1.5 I 100. 0 100. 0 100. 0 100.0 100.0 100.0 100.0

PROPERTIES OF THE EMULSIONS 1 Emulsion stable for 1 2 Ex. 2: Unstable.

3 Ex. 3: Unstable. hours.

day. Separates into 2 emulsion layers in 3 days. after 6 months. Forms stable emulsion when diluted, can be boiled.

Total separation and no redispersion after 5l0 minutes.

Separation begins within 5-10 minutes. Total separation and no redispersion after 12 4 Ex. 4: No emulsion. Water phase too thick. Cannot be dispersed.

5 Ex. 5: Stable for 1 day. shaking. Cannot be diluted. Formsno emulsion in wate Ex. 6: Stable for 1 day. Separates into 2 clear phases in 3 s baking. Cannot be diluted. Forms no emulsion in water.

Redispersed by simple shaking Separates into 2 clear phases in 3 days and cannot be redispersed by vigorous days and cannot be redispersed by vigorous 7 EX. 7: Stable for 1 day. Separates into 2 clear phases in 3 days and cannot be redispersed by vigorous shaking;

Cannot be diluted. Forms no emulsion in water.

It is noticeable that while emulsion number 1, which is an emulsion of the preferred type herein disclosed has about the same stability as a complete emulsion, as others, particularly composi tions 5, 6 and 7, when separation does occur, the material still remains as two emulsion phases rather than two clear phases, even after 6 monthsstorage. The material by simple shaking may be redispersed to form an emulsion. Further, that the material of column 1 can be diluted with water still forming a stable emulsion and that this dilute emulsion can be boiled thus demonstrating a veryconsiderable difference in nature between the materials herein disclosed and somewhat related materials common in the art.

This case is a continuation-in-part of our application Serial No. 562,902 filed November 10, 1944, now abandoned.

We claim: 2

1. A metal cleaning composition in the form of an oil-in-water type emulsion which comprises: a dispersed phase of a substantially water-insoluble solvent selected from the group consisting of orthodichlorbenzene, and mixtures of orthodichlorbenzene and hydrocarbon solvents boiling in the kerosene boiling range, a continuous phase of a strong aqueous solution of hydrochloric acid in which the concentration of HCl is within the range about 17.4 to 38 percent by weight and about 0.1 percent to about 5.0 percent by weight of the emulsion of l-hydroxyethyl 2-heptadecenyl glyoxalidine as an emulsifier. V

2. A metal cleaning fluid in the form of an oilin-water type emulsion which comprises a dispersed phase of a mixture of kerosene and orthothe concentration of HCl is within the range about 17 .4 to 38.0 percent by weight, and between about 0.1 percent and about 5.0 percent by weight of the emulsion of 1-hydroxyethylZ-heptadecenyl glyoxalidine as an emulsifier.

3. A metal cleaning fluid for cleaning rust, scale and grease from the surface of fluid-circulated cooling system, in the form of an oil-inwater type emulsion which comprises a dispersed phase of a mixture of kerosene and orthodichlorbenzene, a continuous phase of a hydrochloric acid aqueous solution, and about 0.1 percent to about 5.0 percent by weight of the emulsion of l-hydroxyethyl 2-heptadecenyl glyoxalidine asan emulsifier, the concentrations of HCl in said emulsion amounting to at least about 10 grams per liter.

ARTHUR. C. PABST. ELEANOR S. SALMON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

1. A METAL CLEANING COMPOSITION IN THE FORM OF AN OIL-IN-WATER TYPE EMULSION WHICH COMPRISES: A DISPERSED PHASE OF A SUBSTANTIALLY WATER-INSOLUBLE SOLVENT SELECTED FROM THE GROUP CONSISTING OF ORTHODICHLORBENZENE, AND MIXTURES OF ORTHODICHLORBENZENE AND HYDROCARBON SOLVENTS BOILING IN THE KEROSENE BOILING RANGE, A CONTINUOUS PHASE OF A STRONG AQUEOUS SOLUTION OF HYDROCHLORIC ACID IN WHICH THE CONCENTRATION OF HC1 IS WITHIN THE RANGE ABOUT 17.4 TO 38 PERCENT BY WEIGHT AND ABOUT 0.1 PERCENT TO ABOUT 5.0 PERCENT BY WEIGHT OF THE EMULSION OF 1-HYDROXYETHYL 2-HEPTADECENYL GLOXALIDINE AS AN EMULSIFIER. 